Page 425 of 2267
YEC814
BATTERY
Refer to EL-POWER.: Detectable line for DTC
: Non-detectable line for DTC
EGRC-
SOLENOID
VA LV E A ENGINE
CONTROL
MODULE
RELAY
ECM EGRC-
SOLENOID
VA LV E B
TROUBLE DIAGNOSES 16CD20T
EGRC-Solenoid Valve (Cont'd)
EC-131
Page 426 of 2267

DIAGNOSTIC PROCEDURE
INSPECTION START
(Circuit for EGRC-solenoid valve A)
CHECK MAIN POWER SUPPLY.
Refer to Trouble Diagnosis for main
power supply (EC-CD-59)
CHECK POWER SUPPLY.
1. Turn ignition switch to the ªLOCKº
position.
2. Disconnect EGRC-solenoid valve A
harness connector.
3. Turn ignition switch to the ªONº posi-
tion.
4. Check voltage between connector
terminal
p2and engine ground.
Voltage: Battery voltage
OK
ENG
Check the following:
lHarness continuity
between ECM relay
and EGRC-solenoid
valve A connector.
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch to the ªLOCKº
position.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM harness connector terminal
208and EGRC solenoid valve A
connector terminal
p1.
Continuity should exist.
If OK, check harness for short-cir-
cuit.
OK
ENG
Check the following:
lHarness for open or
short-circuit between
ECM and solenoid
valve.
If NG, repair harness or
connectors.
CHECK COMPONENTS
(EGRC-solenoid valve).
Refer to ªCOMPONENT INSPECTIONº
EC-CD-135.
OK
ENG
Replace malfunctioning
component(s).
Disconnect and reconnect harness
connectors in the circuit. Then retest.
Trouble is not fixed
Check ECM pin terminals for damage
or the connection of ECM harness con-
nector. Reconnect ECM harness con-
nector and retest.
INSPECTION END
EGRC solenoid valve A
harness connector
NEF219A
EGRC solenoid
valve A harness
connector
NEF220A
H
H
H
H
H
H
H
TROUBLE DIAGNOSES 16CD20T
EGRC-Solenoid Valve (Cont'd)
EC-132
Page 427 of 2267
DIAGNOSTIC PROCEDURE
INSPECTION START
EGR CONTROL OPERATION
CHECK OVERALL FUNCTION.
1. Start engine and warm it up suffi-
ciently. (Air conditioner is ªOFFº).
2. Perform diagnostic test mode II
(Self-diagnostic results).
Make sure that diagnostic trouble
code No. 55 is displayed.
3. Make sure that EGR diaphragm
moves up and down (Use your finger
or a suitable tool) under the following
conditions:
At idle:
Spring does not move.
Racing engine from idle to 2800
rpm:
Spring moves up and down.
NG
EOK
INSPECTION END
CHECK VACUUM SOURCES TO EGR
VA LV E .
1. Disconnect vacuum hoses to EGR
valve.
2. Make sure that vacuum exists under
the following conditions:
At idle:
Vacuum should not exist.
Racing engine from idle to 2800
rpm:
Vacuum should exist.
NG
EOK
CHECK COMPONENTS
(EGR valve).
(See page EC-CD-135.)
NG
Replace malfunctioning
component(s).
pA
NEF433
EGR
valve
NEF434
EGR
valve
H
H
H
H
TROUBLE DIAGNOSES 16CD20T
EGRC-Solenoid Valve (Cont'd)
EC-133
Page 428 of 2267

pA
CHECK CONTROL FUNCTION.
1. Turn ignition switch to ªONº
position.
2. Turn EGRC-solenoid valve A
ªONº and ªOFFº in ªACTIVE
TESTº mode with CONSULT-II
and check operating sound.
----------------------------------------------------------------------------------------------------------------------------------------OR----------------------------------------------------------------------------------------------------------------------------------------
1. Check voltage between EGRC
solenoid valve A connector ter-
minal
p1, and ground with
tester under the following condi-
tions:
Voltage:
At idle
Battery voltage
Engine speed is 2,800 rpm
Approximately 0.4V
NG
EOK
CHECK VACUUM
HOSE.
Check vacuum hose
for clogging, cracks or
improper connection.
Perform electrical circuit inspection.
Refer to EC-CD-132.
OK
pB
C2ESA01
NEF435
NEF846
Crack
Clogging
Improper connection
.
NEF436
.EGRC-solenoid valve
harness connector
H
H
H
TROUBLE DIAGNOSES 16CD20T
EGRC-Solenoid Valve (Cont'd)
EC-134
Page 429 of 2267
COMPONENT INSPECTION
EGR valve
Apply vacuum to EGR vacuum port with a hand vacuum pump.
EGR valve spring should lift.
If NG, replace EGR valve.
EGRC-solenoid valve
Check air passage continuity.
ConditionAir passage
continuity
between
pAandpB
Air passage
continuity
between
pAandpC
12V direct current sup-
ply between terminals
p1andp2
Ye s N o
No supplyNo Yes
If NG, replace solenoid valve.
MEF137D EGR valve
MEC488B BATTERY FUSE
TROUBLE DIAGNOSES 16CD20T
EGRC-Solenoid Valve (Cont'd)
EC-135
Page 430 of 2267
Brake Switch
The ECM receives signals from two brake switches. One is a
conventional brake lamp switch, the other is referred to as a
redundant (RDNT) brake switch.
In case the accelerator pedal does not return to the idle position
(pedal sticks), the driver will react by depressing the brake. In
this (emergency) situation, the ECM will disregard the accelera-
tor pedal signal and bring back the engine speed to 1200 rpm.
Malfunction is detected when ...Check Items
(Possible Cause)
lBrake switch circuits are open or shorted.lHarness or connectors
(Brake switch circuits are open or shorted.)
lStop lamp switch
lRDNT brake switch
DIAGNOSTIC TROUBLE CONFIRMATION
PROCEDURE
1) Turn ignition switch to ªONº position and select ªDATA
MONITORº mode with CONSULT-II.
2) Depress brake pedal for at least 1 minute.
TROUBLE DIAGNOSES 17CD20T
EC-136
Page 431 of 2267
YEC103A
TROUBLE DIAGNOSES 17CD20T
Brake Switch (Cont'd)
EC-137
Page 432 of 2267

INSPECTION START
(RDNT brake switch)
CHECK POWER SUPPLY.
1. Turn ignition switch to ªLOCKº posi-
tion.
2. Disconnect RDNT brake switch har-
ness connector.
3. Turn ignition switch to ªONº position.
4. Check voltage between RDNT brake
switch harness connector terminal
p1and body ground.
Voltage: Battery voltage
OK
ENG
Check the following:
lHarness connectors
F104,M50
(RHD models)
lHarness connectors
F2,E43
(LHD models)
lHarness for open or
short-circuit between
RDNT brake switch
harness connector ter-
minal
p1and ECM
connector terminal
416.
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªLOCKº posi-
tion.
2. Check harness continuity between
RDNT brake switch harness connec-
tor terminal
p2and body ground.
Continuity should exist.
If OK, check harness for short-
circuit.
OK
ENG
Repair harness or con-
nectors.
CHECK COMPONENT.
(RDNT brake switch)
Refer to ªCOMPONENT INSPECTIONº
on next page.
OK
Disconnect and reconnect harness
connectors in the circuit. Then retest.
Trouble is not fixed
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM har-
ness connector and retest.
INSPECTION END
YEC377
RDNT brake switch
harness connector
YEC378
RDNT brake switch
harness connector
H
H
H
H
H
H
TROUBLE DIAGNOSES 17CD20T
Brake Switch (Cont'd)
EC-138